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Patient-Cooperative Control Strategies for Coordinated Functional Arm Movements


F. Oldewurtel

Diploma Thesis written at the Spinal Cord Injury Center of Uniklink Balgrist.

Task-oriented repetitive movements can improve muscular strength and movement coordination in patients with neurological disabilities like stroke or incomplete spinal cord injury. It is believed that training of activities of daily living motivates the subject and helps to relearn functional movements. Activities of daily living consist of coordinated movements, where both position and orientation of the human hand need to be considered. In this thesis, it is investigated how these movements can be trained using the arm therapy robot ARMin. For this, two different control schemes for force reflection, impedance control and admittance control are analyzed. A controller for ARMin is developed on this basis such that ARMin is partially impedance and partially admittance controlled. Weight compensation, redundancy control and friction compensation are added. In order to find a suitable task for the training of activities of daily living with ARMin, coordinated functional arm movements are analyzed. A glass moving task is chosen to be implemented on ARMin and a patient-cooperative support is developed for this task. The support ensures that the robot and the subject interact and that the robot supports the subject in the desired movement just as much as needed without restricting him to a rigid pattern. A stability paradigm for haptic simulation is introduced and applied to ARMin. The developed strategy is first simulated and then implemented on the audiovisual display. The setup is tested and a key figure for assessing the subjectís performance is developed. First results of tests with healthy subjects show that the new strategy can support the subjects in a physiological way. The patient-cooperative support for a therapy robot in three dimensional space is completely novel. Using this support, the patient can be effectively supported in the training of coordination of hand position and orientation. The implementation of activities of daily living has great potential to increase the subjectís motivation and to improve the transfer of learning effects into daily living. Supervisors: T. Nef, M. Mihelj, Prof. R. Riener


Type of Publication:

(12)Diploma/Master Thesis

R. Riener

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% Autogenerated BibTeX entry
@PhdThesis { Xxx:2006:IFA_2433
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